1. Field of the Invention
The present invention relates to a concave type vehicle wheel rim and more specifically, to a wheel rim cover mounting structure, which ensures connection tightness between the wheel rim cover and the concave wheel rim.
2. Description of the Related Art
A concave wheel rim is a particular steel rim for car. An ordinary wheel rim cover cannot be used to cover a concave wheel rim, i.e., a concave wheel rim must be covered with a particular wheel rim cover.
A conventional wheel rim cover 100 for covering a concave wheel rim 30, as shown in FIG. 1, comprises a plurality of retaining troughs 101 protruded from the back side of the cover body 10 and equiangularly spaced along the border for receiving a respective hook plate 20. Each hook plate 20 has a hook portion 201 hooked on the peripheral edge 301 of the concave wheel rim 30 (see FIGS. 2 and 3).
In order to keep the rotation of the concave wheel rim 30 in balance, counterweights (not shown) may be fastened to the border area of the wheel rim 30. The counterweights may hinder the installation of the hook plates 20. In this case, the wheel rim cover 100 may not fit the surface of the concave wheel rim 30 perfectly, and the wheel rim cover 100 may be forced out of place or away from the concave wheel rim 30 upon a vibration of the car.
The wheel rim cover 100 further comprises a plurality of equiangularly spaced through holes 102 cut through the front and back sides of the cover body 10 corresponding to the mounting slots 302 of the concave wheel rim 30 (see FIGS. 1 and 2), a plurality of protruding flanges 103 perpendicularly protruded from the back side of the cover body 10 around the border of each of the through holes 102, a plurality of plugholes 104 respectively provided at two sides of each of the protruding flanges 103, and a plurality of retaining spring plates 40 respectively plugged into the plugholes 104 and secured to the peripheral edges of the mounting slots 302 of the concave wheel rim 30 to lock the wheel rim cover 100 to the concave wheel rim 30.
This design still cannot eliminate the aforesaid drawback, i.e., the counterweights at the concave wheel rim 30 may hinder the installation of the hook plates 20 or affect the connection tightness between the hook plates 20 and the concave wheel rim 30. Further, because two retaining spring plates 40 are provided at two sides of each protruding flange 103 and stopped against two opposite side edges of the corresponding slot 302, the connection tightness between each protruding flange 103 and the associating mounting slot 302 is not good. When the car is moving over an uneven road surface, the retaining spring plates 40 may be forced to move relative to the associating mounting slots 302 or even to escape from the associating mounting slots 302. Further, the sharp side edges of the retaining spring plates 40 may scratch the surface of the concave wheel rim 30 during installation. A scratch surface damage may cause the concave wheel rim 30 to rust easily.